The present invention relates to an apparatus for gripping, locking in position and moving underwater craft and the like, in particular from aboard ships, provided with a self-propulsion device for hitching to the craft to be recovered.
It is known how, at sea, various types of underwater craft are used both for civil and military purposes, being launched onto the water and then recovered from aboard ships equipped for this purpose.
The operations of launching out to sea and recovering these craft are, however, always particularly difficult, because of the difficulty in manoeuvring them, resulting from the impossibility of maintaining a stable relative position between the craft in the water and a hitching device which is normally attached to the ship, due to the movement of the waves which may produce substantial displacement of both the craft and the ship.
This variation in the relative position of the craft with respect to the ship both in the horizontal plane and in the vertical plane therefore complicates the craft gripping operations, very frequently resulting in the need to use personnel in the water who directly perform the operation of attaching the hook of a lifting crane to the craft gripping point; in view of the closeness to the edge of the ship, this results in dangerous and high-risk conditions for said personnel, whose presence in the water is required in particular in bad weather conditions and rough sea conditions which obviously increase further increase the risks.
In the art, some conventional solutions which envisage hitching up the craft by means of a hook situated at the end of a cable which leads to the winch of a crane are known.
These solutions, however, in addition to not allowing gripping of the craft, have the drawback consisting in the fact that, at the moment of lifting of the craft from the water, the said craft is not firmly attached and therefore is able to swing and/or rotate about the vertical axis, increasing the difficulty of manoeuvring for transferral thereof into the parking position on-board the ship; the operating personnel in this case must fasten the craft to other auxiliary means, for example ropes, in order to avoid or reduce these swinging movements and rotations.
This, however, results in other difficulties and risks during the operation in particular when the ship is subject to intense movement. EP 0,532,096 in the name of the same Applicant also discloses an apparatus for gripping, locking in position and moving underwater craft and the like, comprising a crane mounted on-board a ship and provided at its free end with a gripping device, wherein said device essentially consists of a guide element arranged on floats and provided with non-return means for clamping a fixed element attached to the craft to be lifted, as well as means for detecting the position of the mast with respect to the guide, and means for performing movements of the crane arms which, together with the action exerted by the floats, keep a constant distance between the gripping device and the surface of the water and which, together with rotation which can be performed from the crane tower, allow movement of the device parallel to the surface of the water, means also being provided for keeping the device in a vertical position with respect to the ship.
This device has, however, limitations consisting in the need for a dynamic response from the lifting crane, the size of which depends on the weight of the craft to be lifted, which therefore cannot exceed given dimensions since the dynamics of the crane would not be such as to be able to compensate for the relative movements.
In addition to this, the radius of action of the apparatus is limited to the length of the crane arms and consequently the craft to be recovered must be manoeuvred in the vicinity of the hull of the recovery ship so that its gripping element may be introduced with a certain headway into the recovery device, resulting in the risk of collision and damage in particular in rough sea conditions and/or poor visibility.
With the known apparatus, moreover, it is not possible to recover passive floating craft which do not have their own propulsion means.
The technical problem which is posed, therefore, is that of providing an apparatus for hitching to and moving underwater craft and the like, which is able to perform hitching of the craft in the water, with or without its own propulsion means, in a safe manner and without personnel operating in the water, also in the worst conditions as regards weather, rough seas and poor visibility, and which also allows firm gripping and stable positioning of the craft, preventing oscillation and/or rotation thereof.
The apparatus must, moreover, be easy to assemble, also on ships already provided with devices of the conventional type, and able to be converted into auxiliary service apparatus for operations of the conventional type.
These results are obtained by the present invention which envisages an apparatus for gripping and moving underwater craft and the like, comprising a crane mounted on-board a ship and provided with articulated arms and a crane cable, said crane being connected at its free end to a device for gripping the craft to be recovered, wherein said device essentially consists of a head pivotably mounted on the free end of the arm of said crane and able to pivot with respect thereto; and a gripping unit mounted on floats and provided with propulsion means which are controllable by associated means and allow movement of the device parallel to the surface of the water.